In the field of extruding foodstuffs, EP 0 130 772 B1 describes a method of continuously co-extruding two dissimilar materials, i.e. an outer tube consisting of dough and an inner core surrounded by the outer tube so as to produce an extrudate rope. The extrudate rope is deposited on a horizontal conveyor and pressed in a transverse direction so as to seal the outer tube to itself and separate individual dough pieces.
U.S. Pat. No. 5,194,283 is related to co-extrusion of different types of cheese.
Finally, DE 296 20 117 U1 describes a combination of two slices of process cheese, which are sealed all around their circumference so as to enclose a filling in between.